Process for making spreads and spreads made by the process

ABSTRACT

A process for preparing a very low fat water-in-oil spread and a spread made by the process. The process entails a cold mixing procedure wherein an at least partially pre-gelled aqueous phase is mixed with an at least partially pre-solidified fat continuous emulsion of fat and water. Emulsions of less than 30% fat and even 20% or less fat may be prepared.

This application is a continuation of U.S. Ser. No. 08/335,568, filedNov. 7, 1994, now abandoned, which is a continuation of U.S. Ser. No.08/084,752, filed Jun. 29, 1993, now abandoned, which is a continuationof U.S. Ser. No. 07/822,503, filed Jan. 17, 1992, now abandoned.

BACKGROUND OF THE INVENTION

Studies have suggested the need for individuals to reduce their intakeof fat, particularly saturated fat, to minimize the risk of cardiac andother diseases. Moreover, the reduction of overall calories ingested hasbeen of interest to prevent obesity, which has been linked to diabetes,heart disease and other ailments.

In recognition of the need to reduce intake of fat and to decrease thetotal number of calories consumed, efforts have been undertaken toreduce substantially the amount of fat and the overall calorie count ofbread spreads, including those which function to replace butter. Forreasons of microbiological stability and resemblance to butter, it isdesirable that such spreads be fat-continuous. However, as the amount offat is decreased below 35%, and particularly below 30%, it becomesincreasingly difficult to formulate a stable, fat-continuous spreadwhich is acceptable to consumers. Factors related to consumer acceptanceof a spread include the ease of spreading on bread and the similarity tobutter of its melting characteristics, both on bread and in the mouth.

Izzo et al. U.S. Pat. No. 4,882,187 discloses a process for preparing anedible spread having a lower fat content than butter or margarine. Theprocess includes admixing with an aqueous composition a plasticdispersion having a continuous fat phase and a discontinuous aqueousphase. The dispersed aqueous phase has a pH above 4.7 and containsproteins whereas the aqueous composition has a pH at or below 4.7,contains hydrocolloid and is substantially free of milk and soy protein.The mixture of the continuous fat phase and the aqueous composition isworked at a temperature at which the fat-continuous phase remainsplastic. Izzo et al. discuss the use of either high or low shear.

The Izzo et al. spread is said to include one fat phase and two distinctaqueous phases. The need for emulsifiers is said to be reduced oreliminated. Particularly good results are said to be obtained whenbutter is used as the fat-continuous plastic dispersion, although it issaid that common margarine may be employed. It is said that spreadshaving as little as 26% fat have been prepared in accordance with theIzzo et al. invention without the assistance of emulsifiers; thepreferred range is 30-65% fat. Preferred products are said to be madewith butter and gelatin solutions, and in discussing the temperaturerange of the gelatin solution it is stated that once the gelatinsolution has gelled, the resulting product is grainy and has poororganoleptic qualities.

Lissant et al. U.S. Pat. No. 4,844,620 describes a process for preparinga high-internal-phase-ratio emulsion, such as a low fat spread, whereinthe external and internal phases have highly disparate viscosities.Lissant et al. feed their phases into a recirculation line whichincludes a pump, a shearing device, an outlet for removing some of theproduct for packing and an inlet for recirculating part of the product.The spread of the Lissant et al. example includes emulsifiers, sodiumbenzoate and citric acid. It is said that the modifying component isdissolved in the external phase. Lissant et al. do not appear toindicate that their aqeuous phase should be gelled.

EP 011,891 indicates that low fat spreads can be improved by includingin the continuous fat phase a discontinuous aqueous phase consisting ofnon-gelled, liquid finely dispersed droplets having a size range from 1to 5 microns and a second discontinuous aqueous phase consisting ofcoarse, gelled spherical droplets having a diameter in the range of from10 to 20 microns. One or both of the aqueous phases may include protein,e.g., milk protein. Emusifiers may also be included.

The '891 publication states that gelling can be effected before, butpreferably during, emulsification of the fatty and liquid aqueousingredients. Also, it is indicated that emulsions can be prepared byusing gelled spherical ingredients that have been obtained byemulsifying a liquid gelling agent containing aqueous phase in a fattyphase, letting the gelled spherical ingredients form in situ and byblending the emulsion obtained with another fat-continuous emulsionscontaining dispersed liquid aqueous phase. In Example 1, twowater-in-oil emulsions are mixed in a scraped surface heat exchanger(Votator A unit) at temperatures of 17° C. and 20° C., cooled to 0° C.and packed at 17° C.

Gould et al. U.S. Pat. No. 4,520,037 discloses a fat-continuous emulsioncomprising at least two distinct aqueous phases each of which comprisesa microbiologically labile nutrient such as milk protein, vegetableprotein, glucose, lactose or partially hydrolyzed starch. Antibacterialcompounds or preservatives are concentrated in each of the two aqueousphases. The inclusion of emulsifiers is preferred.

Moran GB 1,094,268 discloses a spread for bread comprising awater-in-fat emulsion having 20 to 50% fat wherein the aqueous phasecontains a thickening agent and the fat phase includes an emulsifier.One method of preparing the products comprises emulsifying the aqueousphase containing the thickening agent in the partially crystallized fatcontaining the emulsifier. Prior to mixing, both the aqueous phase andthe fatty phase are preferably cooled to temperatures well below theupper melting point of the fat, e.g., between about 25° C. and 45° C.Alginate ester may be used as the thickening agent.

EP 199 397 discloses a process for preparing an edible fat containingproduct wherein a fat-containing fraction is cooled to causecrystallization of part of the fat and a fraction is mixed with thepartially crystallized fraction in a mixer including a pattern ofcavities. Protein, gelling and thickening agents are mentioned aspossible ingredients. It is said that low fat spreads having acontinuous fat phase and a dispersed aqueous phase may be obtained. Theamount of crystallized fat is preferably at least 2%. Preferably onefraction comprises at least 80% fat and the other fraction is an aqueoussolution or a dispersed system having a continuous aqueous phase. Theaqueous phase may contain gelling agents such as gelatin and protein.

In Example 3, of the '397 document, the aqueous phase is a cream whichincludes milk protein and gelatin.

GB 2 021 140 discloses dairy blends intended to have improvedspreadability compared to butter at refrigeration temperatures. Thewater content can vary from about 10% up to 45% by weight of the totalcomposition. In Example 1, a dairy blend which appears to beapproximately 65% fat by weight is prepared by softening butter to 30°C. and mixing therewith a partially gelled solution including gelatinand water. Rape seed oil is then added. In Example 3, milk is usedinstead of water.

Cain et al. U.S. Pat. No. 4,917,915 discloses spreads containing lessthan 35 wt. % fat which can be obtained by using a gel-forming aqueousphase having a viscosity of at least 20 mPa.s at 5° C. at a shear rateof 17090 sec⁻¹.

SUMMARY OF THE INVENTION

It has now been discovered that stable, fat-continuous emulsions havingfat levels of less than 30%, especially less than 25%, and even lessthan 20% can be prepared by a cold mixing procedure whereby an aqueouscomposition including one or more gelling and/or thickening agents ismixed with an at least partially pre-solidified fat-continuous emulsionof fat and water. The gelling and or thickening agents are present inthe aqueous composition at a concentration at or above the criticalconcentration required for gelling of the agent or combination ofagents. Preferably, the aqueous phase is at least partially pre-gelled.At no point after mixing does the temperature exceed the melting pointof the fat-continuous phase or the gel setting temperature of theaqueous phase. Preferably fats of vegetable origin are employed.Desirably, at no point after mixing is a water-continuous productformed. The emulsions are advantageously used as bread spreads,particularly plasticized bread spreads.

Preferably, the aqueous composition includes less than 50% fat,especially less than 20%; most preferably the aqueous composition issubstantially fat-free. If there is any fat present in the aqueouscomposition, it is dispersed so that the aqueous composition iswater-continuous. Desirable gelling characteristics may be achieved bygelling the aqueous composition with gelatin alone or with mixtures ofgelatin and rice starch and/or waxy maize starch.

In accordance with the invention, just prior to mixing with the aqueousphase, the fat-continuous emulsion is at least partially crystallized.Preferably the temperature and composition of the fat-continuousemulsion just prior to mixing with the aqueous composition is such thatat least 1% by weight is crystallized, particularly at least 3% iscrystallized, and ideally from 3 to 15% is crystallized thefat-continuous emulsion is preferably semi-solid prior to mixing.

In accordance with a second, optional, aspect of the invention, both theaqueous composition and the aqueous phase of the fat-continuous emulsionmay include milk protein and/or soy protein, preferably milk protein.

The mixing of the aqueous composition and the fat-continuous emulsioncan occur under either low or high shear. It has been found thatparticularly favorable results are obtained when there is substantialback-mixing. In an ideally back mixed mixer, the mixing is uniform sothat the emulsion microstructure is the same throughout the interior ofthe mixer starting from a point just beyond the inlet to the mixer. As aresult of the back-mixing, gelled aqueous phase is dispersed almostinstantly into the fat continuous emulsion already present in the mixer.At no point in the mixer should there be a region of water-continuousemulsion. Substantial back-mixing is obtained by recirculating productto the mixer or by using a mixer specially designed to produceback-mixing internally. Since cavity transfer mixers do not per seimpart back-mixing, they may not be used to mix the aqueous phase withthe fat-continuous emulsion, at least absent recirculation means.

In accordance with a further preferred aspect of the invention, thepresent low fat emulsions have a particular structure in that theaqueous phase is formed of two distinct types of droplets, a generallyspherically shaped droplet and a non-spherically shaped droplet havingthe critical gelling concentration of the gelling and/or thickeningagents or combination thereof. The non-spherical droplet may be of apolygonal or other non-spherical shape. Generally the shape of thenon-spherical droplets is irregular and it includes non-curved portions.

The emulsions of the invention are preferably plasticized.

For a more complete understanding of the above and other features andadvantages of the invention, reference should be made to the followingdetailed description of preferred embodiments and to the accompanyingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of the process according to the invention.

FIG. 2 is a cross section of a mixer which can be used in the process ofthe invention.

FIG. 3 is a photograph of the spherical and non-spherical particlesaccording to the invention.

DETAILED DESCRIPTION OF THE INVENTION

The emulsions/spreads of the invention are made by a process wherein afat-continuous emulsion and an aqueous composition are combined,preferably on a continuous basis. In accordance with one aspect of thepresent invention, at the time that the phases are combined, thetemperature of the fat-continuous emulsion is less than the completemelting point for the fat-continuous emulsion. That is, there is stillcrystallized fat in the fat-continuous emulsion when it is combined withthe aqueous phase.

The maximum temperature for the fat-continuous emulsion prior tocombination with the aqueous composition will vary, depending on thecomposition of the phase. The temperature of the combined aqueouscomposition and fat emulsion should likewise be limited from the timethat they are combined through the completion of the packing of theproduct so that the temperature does not exceed that which is necessaryto preserve at least some crystallized fat.

In contrast with the Lissant, et al. patent mentioned above, the presentinvention involves mixing of fat-continuous and aqueous compositionshaving viscosities which are similar. In general, the ratio ofviscosities, at the shear rate applied in the mixer, of the aqueouscomposition to the fat-continuous emulsion which is mixed therewithshould be from 0.2 to 5.0, preferably 0.5 to 2.

The starting fat-continuous emulsion comprises fat and water. Generally,the fat-continuous emulsion prior to mixing with the aqueous compositionwill contain from 0 to 60%, preferably from 15 to 35%, of an aqueousphase dispersed therein. It is also preferred that the fat blend have anN-value at 10° C. of at least 6% and no greater than 55%. The N-value ismeasured by the nuclear magnetic relaxation technique and is a directmeasure of the level of solid fat content at a given temperature. Anappropriate procedure is described in Fette, Seifen, Anstrichmittel80(5), 180-186 (1978).

Optional ingredients in the fat-continuous emulsion which is combinedwith the aqueous composition include emulsifiers, salt (particularlysodium chloride), preservatives, flavors, protein, vitamins, especiallyfat soluble vitamins such as Vitamin A, antioxidants, antimicrobials,and preservatives, including citric and other acids. The emulsifiers caninclude mono- and diglycerides, partial polyglycerol esters, lecithinand polyoxyethylene sorbitan monoesters such as TWEEN 60 and TWEEN 80.One advantageous emulsifier is a polyglycerol polyricinoleate sold underthe name Admul Wol available from Quest International, Naarden, theNetherlands.

Emulsifier may be included at from 0.05 to 2% by weight, typically notmore than 1% by weight.

It is preferred that the fat used be triglyceride fat derived fromvegetable sources including soybean, corn, sunflower, palm, palmkernal,rapeseed, coconut, safflower, cottonseed, peanut and olive oils. Otherdigestible fat sources which may be used are fish oil, milk fat, skimmilk fat, butterfat, lard and tallow. The oil will be hardened byhydrogenation if that is necessary to achieve the desired meltingcharacteristics. Also, fractionation and interesterification may be usedto obtain fats of the desired melting range.

Non-digestible fats may also be used as the fat source. Among thenon-digestible fats are included polyol polyesters of C8 to C22 fattyacids such as sucrose polyester, sucrose polyethers, siliconeoils/siloxanes, polycarboxylic acid esters, branched chain fatty acidtriglycerides, neopentyl alcohol esters, dicarboxylic acid esters,jojoba oil and triglycerol ethers. Non-digestible fats may be used asfrom 0 to 100% of the fat, especially from 10 to 90%, and mostespecially from 25 to 75%.

Non-lipid fat replacers may also be used, to provide body to theproduct. These include protein-based fat replacers such as thosedescribed in Singer et al. U.S. Pat. No. 4,961,953 and cellulosicbulking agents such as microcystalline cellulose and carboxymethylcellulose.

Coloring agents, such as beta carotene, paprika, turmeric and annattomay be employed.

The proteins used in the present invention can conveniently be in theform of milk protein from whole, skim or other low fat milk and maycomprise whey proteins (with or without lactose), acid casein andcaseinates. Vegetable protein, such as soy protein, peanut protein,cottonseed protein, and the like may also be used.

In addition to sodium chloride, flavor enhancers which may be employedinclude lactones, lipolyzed butter oils and starter distillates,diacetyl, 2-octanone, butyric acid, hexanoic acid, and other fattyacids, esters of butyric acid, delta-hydroxy acids and their glycerolesters and mixtures thereof.

Preservatives, such as benzoic acid, sorbic acid, phosphoric acid,lactic acid, acetic acid, hydrochloric acid and the soluble saltsthereof may be used. Likewise, the fat-continuous emulsion may includeantimicrobials such as potassium sorbate, sodium sorbate, potassiumbenzoate, sodium benzoate and phosphoric acid.

Antioxidants may include normal propyl gallate, the tocopherols,including Vitamin E, butylated hydroxyanisole (BHA), butylatedhydroxytoluene (BHT), nordihydroguaiaretic acid (NDGA),tertiary-butylhydroquinon (TBQH) and citric acid.

As seen in FIG. 1, fat-continuous emulsion line 10 includes feed tank12, which stores the ingredients used in preparing the fat-continuousemulsion which is mixed with the aqueous composition, i.e., the startingfat-continuous emulsion. Fat-continuous emulsion pump 14 pumps thefat-continuous emulsion into a Votator(R) A-unit 18. An A-unit is ascraped surface heat exchanger. A-unit 18 lowers the temperature of thefat-continuous emulsion.

From unit 18, the fat emulsion is pumped to Votator(R) C-unit 20, whereit is given residence time to crystallize and is mildly worked at from50 to 400 rpm. After the working in the C-unit, the continuous-fatemulsion is pumped into mixer 21.

The aqueous composition comprises water and, optionally otheringredients. A preferred ingredient is one or more gelling agents suchas gelatin. It is advantageous that the aqueous composition is gelled,which in some respects compensates for the lower amounts of fat in theproduct. It is particularly advantageous for the aqueous composition tobe pre-gelled, i.e., gelled prior to combining the aqueous compositionwith the fat-continuous emulsion. Other suitable gelling agents includewaxy maize starch such as Ultra-Tex 2 available from the National Starchand Chemcial Co., Bridgewater, N.J. or a rice starch such as RemyriseAC. A particularly effective combination of gelling agents has proved tobe gelatin and waxy maize or rice starch. Other gelling agents includecarrageenan, and gelling hydrolyzed starch derivatives such as gellingmaltodextrin, for example, Paselli maltodextrin SA2(R).

Hydrocolloids which are thickening rather than gelling agents may alsobe used. Hydrocolloids are described in Zeitschrift furLebensmittletechnologie und Verfahrenstechnk 32 (1981) 6,pp. 253-256.Hydrocolloids in addition to those mentioned above includepolysaccharides such as native and modified starches, cellulosederivatives, pectins, galleon, xanthan gum, agar, Danish agar,furcelleran, gum arabic, guar gum, locust bean gum, algin, andalginates. Hydrocolloids will generally used at levels of from 0.2 to6%, based on total product. It will be appreciated that the gelling andthickening agents may be used in various combinations.

Additional ingredients which may be present in the aqueous compositioninclude salt (particularly sodium chloride), preservatives, such aspotassium sorbate, lactic and other acid, proteins, coloring agents,flavors, antimicrobials, antioxidants and vitamins, particularlywater-soluble vitamins such as the B vitamins.

Proteins, water-soluble coloring agents, flavors, preservatives andantimicrobials and antioxidants useful in the aqueous composition arethe same as those discussed above in connection with the fat-continuousemulsion.

Aqueous composition line 30 includes a run tank 32 for holding theaqueous composition and an aqueous composition pump 34. The aqueousphase is cooled to a temperature below its critical gel-formingtemperature. A scraped surface heat exchanger (A-unit) 36 or any othersuitable cooling device can be used for this purpose. The cooled aqueousphase is then given residence time to allow the thickening agents toform an at least partially gelled aqueous phase. A slowly turningpin-mixer (C-unit) 23 may be used. The amount of residence time requiredwill depend both on the concentration of the thickening agents presentand the temperature used. It is important for the aqueous phase to beadequately gelled; otherwise, it will not be possible to maintain afat-continuous emulsion at the low fat levels contemplated herein.

There are two basic requirements for the mixer: a) there must beadequate shear to disperse the gelled aqueous phase into the semi-solidfat phase and b) there must be a high degree of back-mixing so that thegelled aqueous phase is dispersed almost instantly into thefat-continuous emulsion already present in the mixer. At no point in themixer should there be a region of water-continuous emulsion.

The back-mixing can be internal or external to the mixer depending onthe mixer design. FIG. 2 illustrates a mixer with internal back-mixing.The disclosed mixer is a variation on a standard pin-mixer, except thatit has a ratio of length to diameter (L/D) of about 1 instead of themore common 4-6 found in regular pin-mixers. This geometry combined withhigh shaft rotational speeds (>1000 rpm) results in a mixer that ishighly back-mixed. Other mixers having more of a plug flow effect, suchas regular pin-mixers (L/D of 4-6) and static mixers, have been usedsuccessfully when back-mixing is provided externally with arecirculation loop over the mixer.

One method for quantifying the amount of back-mixing required involvesconsideration of the performance of several different mixers with regardto their dispersion numbers (D_(L) /uL). The dispersion number is awidely recognized chemical engineering term used to describe residencetime profiles in vessels with varying degrees of plug-flow andback-mixing (see Chemical Reaction Engineering, 2nd Edition, by O.Levenspiel. Copyright 1972). Ideal back-mixed mixers have a dispersionnumber of infinity whereas ideal plug-flow mixers have a dispersionnumber of zero. In actuality, all mixers lie somewhere in between theseideal values. Mixers (either internally or externally back-mixed) withdispersion numbers greater than 0.06 are preferred, with values greaterthan 0.1 especially preferred and values of 0.2 or more particularlypreferred.

Mixer 21, best seen in FIG. 2, is specially designed to maximizeback-mixing. Mixer 21 has an L/D ratio of 1. Mixer 21 includes a casing70, fat emulsion inlet 78, aqueous composition inlet 79, product exit80, mixing chamber 82, rotor 84 and mixing pins 86. Exemplary dimensionsfor mixer 21 would be as follows: volume 2.4 L, length 6 inches,diameter 5.8 inches, pin diameter 0.375 inches and shaft diameter 1.5inches.

Post-cooling or post-working devices such as scraped surface heatexchangers or pin-type mixers may be used to refine further the textureof the product.

The fat content of the overall product is preferably less than 30%,especially less than 25% and most preferably less than 20%. It isexpected that the emulsions contain at least 2% fat, more usually atleast 10% fat. Generally, the product will contain at least 15% fat.

As can be seen in the photograph of FIG. 3, which has a 10 micron scalebar, the aqueous phase includes two distinct types of droplets, agenerally spherically shaped droplet and a non-spherically shapeddroplet having the critical gelling concentration of the gelling and/orthickening agents or combination thereof. The non-spherical droplet maybe of a polygonal or other non-spherical shape. Generally the shape ofthe non-spherical droplets is irregular and it includes non-curvedportions.

Although we do not wish to be bound by theory, we presume that thespherically shaped droplets consist primarily of the non-gelling aqueousphase and the non-sperical droplets consist primarily of the gelledaqueous phase.

EXAMPLE 1

A very low fat spread containing 23% continuous fat phase and 77%dispersed aqueous phase was prepared as follows:

An aqueous phase solution was prepared containing the followingingredients:

    ______________________________________                                                        Wt. %                                                         ______________________________________                                        Water             93.47                                                       Gelatin (250 Bloom)                                                                             3.25                                                        Ultra-Tex 2       1.5                                                         Whey Powder       0.5                                                         Salt              1.0                                                         Potassium Sorbate 0.162                                                       Lactic Acid       0.115                                                                         100                                                         ______________________________________                                         Aqueous phase pH 4.8                                                     

The solution was prepared by heating the water up to 85° C. and thengradually adding the dry ingredients with good agitation. After mixingfor approximately 5 minutes, the solution was cooled to 55° C. and thelactic acid was added to obtain a pH of approximately 4.7-4.8. Thesolution was now ready for use.

A fat continuous emulsion was prepared separately with the followingcomposition:

    ______________________________________                                        Lecithin           0.22                                                       Distilled Sat. Mono-                                                                             0.25                                                       glycerides (IV = 4)                                                           Soybean Oil        42.9                                                       Hydrogenated Soybean                                                                             28.6                                                       Oil (MP = 40.5° C.)                                                                       72                                                         Water              25.68                                                      Citric Acid        0.02                                                       Potasium Sorbate   0.05                                                       Whey Powder        1.25                                                       Salt               1.0                                                                           28                                                         ______________________________________                                         Fat Continuous Phase pH: 5.0                                             

This fat blend has the following N-values: N10=28.9, N20=15.1, N30=3.8.

The fat continuous phase was prepared by heating the oils up toapproximately 65° C. and adding the lecithin and already melted,distilled, saturated monoglycerides under moderate agitation. Thesecond, non-gelling aqueous phase was prepared in a separate vessel byheating the water to 85° C. (for pasteurization) and then adding the dryingredients and stirring until dissolved. This aqueous phase was thenadded to the already prepared fat along with small amounts of color andflavor. The entire emulsion was then cooled to 55° C. and was ready foruse.

The aqeuous phase and the fat continuous phase were then processed asfollows:

The aqueous phase was pumped through an A-unit where it was rapidlychilled to 15° C., a temperature well below the critical gellingtemperature of this solution. The aqueous phase was then passed througha C-unit rotating at approximately 100 rpm to prevent channelling whereit was given residence time of about 3 minutes in which it became thickand partially gelled. From there it was diverted into a waste tank untilready for use.

Simultaneously, the fat continuous phase was started by pumping the fatcontinuous emulsion through an A-unit where it was rapidly cooled to 14°C. (well below the alpha-point for this fat blend) and then it waspassed through a C-unit rotating at 300 rpm. Here the fat temperatureincreased from 14° to 22° C. The fat contains approximately 12.8% solidfat at this point. The fat continuous phase was then diverted into awaste tank until ready for mixing.

The flow rates of the two streams were adjusted to give a product of thedesired fat content (23%). In this case the ratio was 32% fat continuousstream/68% aqeuous phase stream.

When all was ready, the fat continuous phase was fed into a highlyback-mixed mixer such as the one described above. Gentle mixing (about300 rpm) was begun in the mixer. When the mixer had completely filledwith fat continuous phase, the partially gelled aqueous phase was thenalso fed into the mixer. At this point the shear was rapidly increased(1400 rpm) so that the fat continuous emulsion was maintained and thegelled aqueous phase entering the mixer was rapidly dispersed into thefat continuous emulsion. The temperature in the mixer increased to 26°C. At this temperature, the fat present contained approximately 8.3%solid fat. From the mixer, the product passed into a C-unit where thetexture was adjusted by gentle shear and then the product was packed inplastic tubs. Initially after start-up, the product was high in fat andwas discarded, but once the process had achieved steady-state, theproduct could be packed as desired.

The product obtained from this process had the following composition:

    ______________________________________                                                         Wt. %                                                        ______________________________________                                        Lecithin           0.07                                                       Distilled Sat. Mono-                                                                             0.08                                                       glycerides                                                                    Soybean Oil        13.7                                                       Hydrogenated Soybean                                                                             9.15                                                       Oil (MP = 40.5° C.)                                                                       23                                                         Water              71.8                                                       Gelatin            2.2                                                        Ultra-Tex 2        1.0                                                        Whey Powder        0.74                                                       Salt               1.0                                                        Potassium Sorbate  0.13                                                       Lactic Acid        0.08                                                       Citric Acid        0.006                                                                         77.0                                                       ______________________________________                                         Serum pH 4.87                                                            

After one week, products from this experiment were measured for hardness(C-values by penetrometer) and conductivity at both 5° and 20° C. Theresults were as follows:

    ______________________________________                                        C-value @ 5° C. (gm/cm.sup.2):                                                                  564                                                  20° C.:           132                                                  Conductivity @ 5° C. (uS):                                                                      7.8                                                  20° C.:           0.3                                                  ______________________________________                                    

These products were judged to have oral melt and appearance propertiescomparable to commercially available gelatin containing spreadscontaining 40% fat.

Spreads with fat contents as high as 27% were also produced in thisexperiment by simply changing the ratio of the two phases andmaintaining the same process conditions. The final product compositionscan be obtained using the starting formulas of the two phases and theratio in which they were mixed. With this aqueous composition, stableproducts below 23% were not obtained.

EXAMPLE 2

The experiment in Example 1 was repeated with the same fat continuousphase. However the following aqueous phase was used to produce a productcontaining an 18.5 wt. % continuous fat phase product:

    ______________________________________                                                        Wt. %                                                         ______________________________________                                        Water             91.97                                                       Gelatin (250 Bloom)                                                                             3.25                                                        Ultra-Tex 2       3.0                                                         Whey Powder       0.5                                                         Salt              1.0                                                         Potassium Sorbate 0.162                                                       Lactic Acid       0.115                                                                         100                                                         ______________________________________                                         Aqueous phase 4.83                                                       

Both the aqueous and the fat phase were prepared, processed and mixedtogether in the same way as described in Example 1. However, the ratiobetween the two phases was adjusted (by changing the flow rates of thetwo streams) to 26% fat continuous phase and 74% partially gelledaqueous phase to give a product with the appropriate fat content givenabove. After treatment in the mixer, in this experiment the product waspassed through a post-cooling A-unit where it was cooled to 22° C. andthen into a post-working unit where the temperature increased to 24° C.before packing.

The final product from this experiment had the following composition:

    ______________________________________                                                         Wt. %                                                        ______________________________________                                        Lecithin           0.056                                                      Distilled Sat. Mono-                                                                             0.064                                                      glycerides                                                                    Soybean Oil        11.0                                                       Hydrogenated Soybean                                                                             7.35                                                       Oil (MP = 40.5° C.)                                                                       18.5                                                       Water              74.9                                                       Gelatin            2.41                                                       Ultra-Tex 2        2.22                                                       Whey Powder        0.69                                                       Salt               1.0                                                        Potassium Sorbate  0.13                                                       Lactic Acid        0.085                                                      Citric Acid        0.005                                                                         81.5                                                       ______________________________________                                         Serum pH 4.91                                                            

These products had conductivities of 8.4 and 1.25 uS at 5° and 20° C.,respectively. Although these products were judged to be substantiallycoarser and thicker in the mouth than the products produced in Example1, they were still of reasonable quality. This was the minimum stablefat level for this experiment.

EXAMPLE 3

The experiment in Example 2 was repeated with the same aqueous phase,however, the following fat continuous formula was used to produce a 20wt. % continuous fat phase product:

    ______________________________________                                                         Wt. %                                                        ______________________________________                                        Lecithin           0.22                                                       Distilled Sat. Mono-                                                                             0.25                                                       glycerides (IV = 4)                                                           Soybean Oil        48.7                                                       Hydrogeanted Soybean                                                                             22.8                                                       Oil (MP = 40.5° C.)                                                                       72                                                         Water              25.68                                                      Citric Acid        0.02                                                       Potassium Sorbate  0.05                                                       Whey Powder        1.25                                                       Salt               1.0                                                                           28                                                         ______________________________________                                         Fat Continuous Phase pH: 5.0                                             

This (softer) fat blend has N-values of N10=20.0, N20=11.0, N30=2.05 andN35=0.45.

The aqueous phase was prepared and processed as in Examples 1 and 2 togive a thick partially gelled solution. The fat continuous phase wasprepared as in Example 1 and pumped into an A-unit where it was rapidlycooled to 12° C. (well below the alpha point). The fat continuousemulsion was then passed into a C-unit where the temperature increasedto 20° C. At this point, the fat contains approximately 11% solid fat.The two phases were mixed in the mixer at the same rpm (1400) as used inExamples 1 and 2 and at a ratio of 27.8% fat continuous phase and 72.2%partially gelled aqueous phase. The mixer temperature was 24° C. due tothe lower fat continuous phase temperature. The fat containsapproximately 7.4% solid fat at this mixing temperature. After themixing step, the product was post-cooled and worked as in Example 2before being packed.

The formulation of the finished 20% fat product was:

    ______________________________________                                                         Wt. %                                                        ______________________________________                                        Lecithin           0.061                                                      Distilled Sat. Mono-                                                                             0.07                                                       glycerides                                                                    Soybean Oil        13.5                                                       Hydrogeanted Soybean                                                                             6.34                                                       Oil (MP = 40.5° C.)                                                                       20.0                                                       Water              73.6                                                       Gelatin            2.34                                                       Ultra-Tex 2        2.17                                                       Whey Powder        0.71                                                       Salt               1.0                                                        Potassium Sorbate  0.13                                                       Lactic Acid        0.083                                                      Citric Acid        0.006                                                                         80.0                                                       ______________________________________                                         Serum pH 4.90                                                            

After one week, products from this experiment were measured for hardness(C-values by penetrometer) and conductivity at both 5° and 20° C. Theresults were as follows:

    ______________________________________                                        C-value @ 5° C. (g/cm.sup.2):                                                                   316                                                  20° C.:           75                                                   Conductivity                                                                  @ 5° C. (uS):     0.75                                                 20° C.:           0.067                                                ______________________________________                                    

These products were found to be slightly softer and more spreadable thanthose produced with the harder fat blends in Examples 1 and 2. Overall,these samples were found to be of good quality.

EXAMPLE 4

The experiment in Example 3 was repeated; however, a static mixer with arecirculation loope was substituted for the internally back-mixed mixer.A Waukesha lobe pump was used to pump the product around therecirculation loop. The formulations and processing conditions for theaqueous phase and the fat continuous phase were the same. The ratiobetween the two phases was also maintained so that a 20 wt % continuousfat phase product would be obtained. The static mixer had 14 elementseach 0.875" in diameter and 1.25" long. The mixer was also jacketed sothat water of controlled temperature could be used to heat or cool theproduct in the static mixer.

When both of the phases were at the appropriate conditions, the staticmixer and the recirclation loop were filled with fat continuous phase.The Waukesha recirculation pump was started and set so that the ratiobetween the amount of product recirculated and the amount of productentering and leaving the loop was approximately 5:1. At this point thepartially gelled aqueous phase was introduced. The temperature leavingthe static mixer was kept at 24.4° C. by adjusting the temperature ofthe jacket water to 36° C. The pressure drop across the static mixer wasapproximately 45 psi. Satisfactory product (with the same composition asin Example 3) was then collected at the recirculation loop outlet. Whenthe experiment was completed, the recirculation pump was switched off toeliminate the backmixing. The product almost immediately became watercontinuous at this point.

EXAMPLE 5

The experiment in Example 4 was repeated using the same partially gelledaqueous phase and fat continuous aqueous phase formulations andprocessing conditions. The phase ratio was kept the same so that a 20wt. % fat product was formed and the same static mixer/recirculationloop combination was used to mix the two phases together. However, inthis experiment, once a stable product was obtained at the staticmixer/recirculation loop at the same mixing temperature, the temperatureof the partially gelled aqueous pahse was increased at the aqueous phaseA-unit until the aqueous phase was clearly no longer gelled but was aliquid at the mixing point. At this time, the quality of the productbegan to deteriorate rapidly until the product was no longer fatcontinuous at the outlet of the static mixer/recirculation loop.

EXAMPLE 6

The experiment of Example 3 was repeated, except that the Ultra Tex 2waxy maize starch was replaced by an equal amount of Remyline AP ricestarch (available from S. C. Revy Industries N.V., Wijgmaal-Leuven,Belgium). The aqueous and fat continuous phases were processed and mixedtogether in the same ratio under the same conditions as described inExample 3. Products containing 20% fat were collected and stored at 5°C. for one week. Overall, these samples were found to be comparable tothose produced in Example 3 with perhaps a slightly improved oral melt.

Unless stated otherwise, all percentages used herein are by weightunless otherwise required by the context. The terms "fat" and "oil" areused interchangeably herein, each referring to compositions includingsubstantial amounts of triglycerides.

It should be understood, if course, that the specific forms of theinvention herein illustrated and described are intended to berepresentative only, as certain changes may be made therein withoutdeparting from the clear teachings of the disclosure. Accordingly,reference should be made to the following appended claims in determiningthe full scope of the invention.

What is claimed is:
 1. A process for making a fat-continuous emulsionhaving less than 30 wt. % fat, comprisinga) mixing an at least partiallypre-gelled, gell-forming aqueous composition having less than 50% fatwith an at least partially pre-solidified fat-continuous water-in-oilstarting emulsion in such a way that at no time during or after themixing step does the temperature exceed the melting point of thefat-continuous emulsion, the resulting emulsion being fat continuous andhaving less than 30 wt. % fat, the aqueous composition and thefat-continuous starting emulsion being mixed together by back-mixing. 2.The process according to claim 1 wherein the mixer includes an externalrecirculation loop which provides back mixing.
 3. The process accordingto claim 1 wherein at no point after the aqueous composition andfat-continuous starting emulsion are mixed is a water-continuousemulsion formed.
 4. The process according to claim 1 wherein the overallfat content of the resulting fat-continuous emulsion product is lessthan 25%.
 5. The process according to claim 4 wherein the overall fatcontent of the resulting fat-continuous emulsion product is less than20%.
 6. The process according to claim 1 wherein the aqueous compositionis at least partially gelled prior to mixing by inclusion of gellingagents selected from the group consisting of gelatin and mixtures ofgelatin with a starch or starch derivative.
 7. The process according toclaim 1 wherein the aqueous composition is at least partially gelled byinclusion of gelatin and rice starch.
 8. A process for making afat-continuous emulsion having less than 30 wt. % fat, comprisinga) backmixing an at least partially pre-gelled aqueous composition includingproteins selected from the group consisting of milk and soy proteinswith an at least partially pre-solidified fat-continuous oil-in-waterstarting emulsion having proteins in its discontinuous aqueous phase insuch a way that at no time during or after the mixing step does thetemperature exceed the melting point of the fat phase, the emulsionthereby produced having less than 30 wt. % fat and being fat-continuous.9. The process of claim 8 wherein the aqueous phase is at leastpartially pre-gelled prior to mixing with the fat continuous startingemulsion.
 10. The process of claim 8 wherein the aqueous compositionincludes at least 0.01 wt. % protein.